41 lines
1.9 KiB
ReStructuredText
41 lines
1.9 KiB
ReStructuredText
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.. currentmodule:: zephyr
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.. _zephyr.FlashArea:
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class FlashArea -- access to built-in flash storage
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===================================================
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Uses `Zephyr flash map API <https://docs.zephyrproject.org/latest/reference/storage/flash_map/flash_map.html#flash-map>`_.
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This class allows access to device flash partition data.
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Flash area structs consist of a globally unique ID number, the name of the flash device the partition is in,
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the start offset (expressed in relation to the flash memory beginning address per partition),
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and the size of the partition that the device represents. For fixed flash partitions, data from the device
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tree is used; however, fixed flash partitioning is not enforced in MicroPython because MCUBoot is not enabled.
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Constructors
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------------
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.. class:: FlashArea(id, block_size)
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Gets an object for accessing flash memory at partition specified by ``id`` and with block size of ``block_size``.
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``id`` values are integers correlating to fixed flash partitions defined in the devicetree.
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A commonly used partition is the designated flash storage area defined as ``FlashArea.STORAGE`` if
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``FLASH_AREA_LABEL_EXISTS(storage)`` returns true at boot.
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Zephyr devicetree fixed flash partitions are ``boot_partition``, ``slot0_partition``, ``slot1_partition``, and
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``scratch_partition``. Because MCUBoot is not enabled by default for MicroPython, these fixed partitions can be accessed by
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ID integer values 1, 2, 3, and 4, respectively.
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Methods
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-------
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.. method:: FlashArea.readblocks(block_num, buf)
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FlashArea.readblocks(block_num, buf, offset)
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.. method:: FlashArea.writeblocks(block_num, buf)
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FlashArea.writeblocks(block_num, buf, offset)
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.. method:: FlashArea.ioctl(cmd, arg)
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These methods implement the simple and extended
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:ref:`block protocol <block-device-interface>` defined by
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:class:`uos.AbstractBlockDev`.
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